1. Field of the Invention
The present invention relates to a button applicator for attaching a pair of button elements such as a combination of a button body and a tack member, a combination of a hook and an eye and the like to a fabric piece by caulking one button element to another button element through the fabric piece, more particularly related to a button applicator, which does not require any adjusting for a resilient force supporting the die, when a button element having different caulking pressure is applied.
2. Prior Art
In order that one button element is caulked to another button element through a fabric piece, usually, a button applicator using a punch and a die is applied. In this case, a press-stroke should be adjusted corresponding to the thickness of the fabric piece by adjusting a stroke with which the punch is brought down or by adjusting a position of the die. If the adjusting operation is not carried out, following problems are caused;
If a fabric piece is changed to a thicker fabric piece in caulking operation without the adjusting of the press-stroke, an exceeding pressure causes damage to the thicker fabric piece and/or to the caulked button elements, for example, the fabric piece is rent.
On the other hand, if the following fabric piece is thinner than the previous one, an insufficient pressure causes unsuitable caulking conditions.
However, it is troublesome that the press-stroke should be changed every time when the thickness of the fabric piece is changed.
In order to solve this problem, apparatuses, which are shown in Japanese patent application No. 41-7905 and Japanese Utility Model Application No. 57-121620, were proposed;
According to this prior art, a spring is provided under a die. An exceeding pressure, which is produced when a fabric piece is changed to another thicker fabric piece, is absorbed by the spring. Therefore, in caulking operation, the fabric piece, which has many kinds of thickness, can be used without the adjusting of the press-stroke.
However, in the apparatus of Japanese patent application No. 41-7905, the resilient force of the spring should be adjusted every time another button element, which has different caulking pressure, is caulked. Since, this adjusting operation is very troublesome, it takes a long time to caulk the button elements using this apparatus.
In order to solve this problem, according to the apparatus of Japanese Utility Model Application No. 57-121620, an adjusting plate, which has a predetermined thickness corresponding to the caulking pressure of each button element, is selected to be inserted under the spring.
However, it is also troublesome to change the adjusting-plate every time when another button element is caulked. As a result, the caulking operation using this apparatus can not be carried out efficiently.